Premix burner

A premix burner, comprising:

• at least two hollow, conically expanding partial bodies stacked inside each other coaxially to a longitudinal axis of the burner, the center axes of which partial bodies extend offset to each other, and the walls of which form tangential inlet channels for combustion air in an overlapping area, and comprising also at least one fuel nozzle inside a chamber formed by the partial bodies, and furthermore comprising a mixing section downstream from a swirl flow generator that is formed by the partial bodies, where said mixing section is provided inside a first initial part with transition channels extending in flow direction for the swirl flow formed in the chamber and ends at a separation edge into a combustor, wherein a free flow cross-section of the mixing section is reduced in the flow direction with a simultaneous change from a cross-section shape that is largely rotation-symmetrical about the central longitudinal axis of the burner to a cross-section shape that is largely non-rotation-symmetrical about the longitudinal axis in that at least one circumferential section of the wall delimiting the mixing section has a smaller distance from the fuel nozzle longitudinal axis in a downstream part than in an upstream part.

A premix burner, comprising:

• a swirl flow generator with means for the tangential introduction of a combustion air stream into a chamber of the swirl flow generator as well as means for introducing at least one gaseous and/or liquid fuel into the combustion air stream with concomitant formation of a swirl flow with an axial movement component towards a mouth of the burner and a burner nozzle at a combustor end of the burner, wherein a free flow cross-section of the burner nozzle is reduced in the flow direction with a simultaneous transition from a cross-section that is largely rotation-symmetrical about a longitudinal axis of the burner into a cross-section that is largely non-rotation-symmetrical about the longitudinal axis, and at least one circumferential section of a wall of the burner nozzle has a smaller distance from the nozzle longitudinal axis in a downstream part than in an upstream part.